Up to now, many methods and apparatus for gasification of the candy have been developed. For example, there are U.S. Pat. Nos. 3,985,909, 3,985,910, 4,001,457, 4,289,794, 5,165,951, etc. These patents disclose the method and apparatus for manufacturing a gasified candy in which a gas is impregnated into the candy melt, which is introduced through the inlet installed in the upper or middle portions of the pressure vessels, by agitating the candy melt using the agitator under the appropriate temperature and pressure. In these patents, different types of gas introduction methods and agitation methods are used. However, these methods have defects in that the gasification of the candy melt by agitation means only, due to the inherent viscosity of the candy melt, is neither smooth nor consistent. Further, in case a large quantity of gas is introduced, the good quality popping effect cannot be attained and, due to the physical property of the candy composition, the foam state is inferior.
Also, the above-described patents disclose only the method and apparatus for injecting a gas into vessels and the agitation method and apparatus for impregnating a gas into the candy melts within the vessels. Accordingly, there are limits the ability to gasify the candy melt.
Therefore, a method and apparatus have been required to manufacture a candy characterized by a superior popping effect by means of impregnating a higher ratio of gas and, at the same time, a comparably uniform foam state impregnated into a candy.